public bool DecodeTeletextData(Pes pes)
{
if (pes.PacketStartCodePrefix != Pes.DefaultPacketStartCodePrefix || pes.StreamId != Pes.PrivateStream1 ||
pes.PesPacketLength <= 0) return false;
ushort startOfSubtitleData = 7;
if (pes.OptionalPesHeader.MarkerBits == 2)
{
startOfSubtitleData += (ushort)(3 + pes.OptionalPesHeader.PesHeaderLength);
}
while (startOfSubtitleData <= pes.PesPacketLength)
{
var dataUnitId = pes.Data[startOfSubtitleData];
var dataUnitLenght = pes.Data[startOfSubtitleData + 1];
if ((dataUnitId == DataUnitEbuTeletextNonsubtitle || dataUnitId == DataUnitEbuTeletextSubtitle) && dataUnitLenght == SizeOfTeletextPayload)
{
var data = new byte[dataUnitLenght + 2];
Buffer.BlockCopy(pes.Data, startOfSubtitleData, data, 0, dataUnitLenght + 2);
//ETS 300 706 7.1
Utils.ReverseArray(ref data, 2, dataUnitLenght);
DecodeTeletextDataInternal(data);
}
startOfSubtitleData += (ushort)(dataUnitLenght + 2);
}
return false;
}
public void AddPacket(TsDecoder.TransportStream.TsDecoder tsDecoder, TsPacket tsPacket)
{
if (_currentTeletextDescriptor == null)
{
Setup(tsDecoder);
if (_currentTeletextDescriptor != null)
{
Debug.WriteLine($"Locked onto teletext PID for {TeletextPid} ");
}
}
if (tsPacket.Pid != TeletextPid) return;
if (tsPacket.PayloadUnitStartIndicator)
{
if (_currentTeletextPes != null)
{
if (_currentTeletextPes.HasAllBytes())
{
_currentTeletextPes.Decode();
foreach (var key in _teletextSubtitlePage.Keys)
{
_teletextSubtitlePage[key].DecodeTeletextData(_currentTeletextPes);
}
}
}
_currentTeletextPes = new Pes(tsPacket);
}
else
{
_currentTeletextPes?.Add(tsPacket);
}
}